Retracting blade switch



June 3, 1941.

T. F. JOHNSON RETRACTING BLADE SWITCH 2 Sheets-Sheet 1 Filed Aug. 15, 1940 zrzwawi'k June 3, 1941. 'r. F. JOHNSON RETRACTING BLADE swrr cn Fiied Aug. 15, 1940 2 Sheets-Sheet 2 Patentecl June 3, 1241 lTe PATENT orrics 21244;.201 aaraaormoe'ema swrron I Tomiinson F. Johnson, Atlanta, Ga.

Application August 15, 1940, Serial No. 352,799

7 Claims. 3 G]. 200-48) This invention relates to electric switches and aims, among other objects, to provide a novel high tension switch of the retractable and swinging blade type having sprocket and chain mechanism for imparting initial straight line movement and swinging movement to the blade. Another aim is to provide such a chain motion to prevent the blade from accidentally swinging toward its closed position after it has been opened. Still another aim is to provide a simple, rugged, cheap and dependable switch of this type which can be operated by a single connecting rod or double jointed link and a crank on the usual type of rotatable insulator.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawings, wherein: f

Fig. 1 is a side elevation of a switch embodying the invention and showing the switch blade in its closed position;

Fig. 2 is a fragmentary side elevation showing the switch blade moved to another position;

Fig. 3 is a top plan view of the switch;

Fig. 4 is a sectional view taken on the line m4 of Fig. l; and

Fig. 5 is a perspective View of one of the sprockets.

Referring particularly to the drawings, the type of switch selected for illustrative purposes i shown as being mounted on the usual channel support It! and a pair of stationary insulators H and 52. It is adapted to be operated by an ordinary rotatable insulator 13 having a stub shaft Id at the top carrying an operating crank arm Hi. It is to be understood that switches of this type are mounted in gangs or multi-phase units, three such units being employed in an ordinary three phase system, and all of them are adapted to be operated by well known mechanism (not shown), connected to operating cranks it.

In this instance, the insulator 12 has the usual cap and conductor terminal I! on which is mounted a powerful spring jaw 88 which is closed at the top to prevent ice from jamming the blade. The switch blade I9 is shown as being of tubular form and flattened at its tip to slide into and out of the jaw. It is connected at its rear end by a bracket .28 constituting one link of a chain 2| composed of a series or" similar links and trained over a pair of square sprockets 22 made of thick ing surfaces for the link pins and prevent the switch blade from swinging laterally or wobbling when it is operated.

Of course, it is to be understood that the sprockets may be of other shapes, square ones being illustrated as being suited for the purpose. They are mounted on axles or pins 2'5 upported in bearing brackets 26 integral with a top plate 2'? on the middle insulator ii. Also, brace arms 23 between the insulators H and I3 are shown as being integral with the opposite rear brackets 26 and they are connected at their rear ends to forwardly extending arms 29 on a plate member carrying the conductor terminal member 3!, said plate being mounted on the shaft it of the rotatable insulator. This serves as a brace between the stationary insulator and the rotatable insulator.

Since the chain links straddle the sprockets, it is necessary to prevent the sprockets from shifting laterally on their shafts, For that purpose, there are shown spacersleeves 32 between the upstanding brackets and the sprockets on each 01 the snaits or axles 25.

To operate the switch, there is shown a collar on the blade lain'iront of the sprocket chain and it is connectecl by an adjustable and double jointed connecting rod 34 to the crank it: on the rotatable insulator it. This connecting rod and the operating mechanism aresubstantially the same as those disclosed in my'Patent 2,194,021. uniy one such connecting "rod is necessary to impart straight line retracting. and closing movement as well as swinging movement to raise and lower the blade.

In the operation of the switch, the first movement imparted to retract the blade is in a substantially straight line rearwardly, he rear end of the blade assumes the position shown in Fig. 2 when the crank arm is initially rotated. It will be noted that when the blade is in that position the sprockets have been turned through an angle of 45. Then the bracket link 20 engages the rear sprocket and the switch blade is moved so that the bracket link 28 assumes the dotted position shown in Fig. l with the blade fully retracted from the jaw but still in a horizontal position. The blade is then free of the jaw and is ready to be swung upwardly. In Fig. 2, the dotted link indicates the initial swinging movement of the blade to substantially a 45 position and in Fig. 1 the blade has been moved to its vertical or fully opened position, as shown by dotted lines. It is to be understood, however, that the switch is adapted to be mounted in any position because of the stable bearings afforded by the sprockets.

From the foregoing description, it will be understood that the switch can be manufactured and sold at a relatively small cost. The parts are simple and rugged in their construction and can be made on a quantity production basis. When the blade is fully opened, it has no tendency to fall closed. Moreover, the simplest actuating mechanism may be employed.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be employed conjointly, since they may be employed advantageously in various combina tions and sub-combinations.

What is claimed is:

1. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a pair of sprockets and a chain mounted on the other insulator; an axially retractable and swinging blade mounted on the chain; and a rotatable operating insulator having blade actuating means connected to impart said movements to the blade.

2. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a pair of sprockets and a chain mounted on the other insulator; an axially retractable and swinging blade mounted on the chain; a rotatable insulator mounted adjacent to said blade supporting insulator; and a crank arm and a single double jointed connecting rod connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto.

3. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a pair of non-circular sprockets and a chain mounted on the other insulator; an axially retractable and swinging blade mounted on the sprocket chain; a rotatable insulator mounted behind said blade supporting insulator; and a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto.

4. In an electric switch of the character described, a pair of spaced insulators; a jaw mounted on one insulator; spaced pairs of upstanding brackets on the other insulator; a pair of sprockets of substantial thickness mounted on said brackets; a chain on said sprockets; a retractable and swinging blade having its rear end supported on the chain; and operating means to impart said movements to the blade.

5. In an electric switch of the character described, a pair of spaced insulators; a jaw mounted on one insulator; spaced pairs of upstanding brackets on the other insulator; a pair of sprockets of substantial thickness mounted on said brackets; a chain on said sprockets; a retractable and swinging blade; a chain link bracket rigidly supporting the rear end of said blade; and a single jointed connecting rod secured to the blade to impart operating movements thereto.

6. In an electric switch of the character described, a pair of spaced insulators; a jaw mounted on one insulator; spaced pairs of upstanding brackets on the other insulator; a pair of thick square sprockets mounted on said brack ets and having pin grooves at their corners; a wide chain on the sprockets having pins guided in said grooves to prevent wabbling; a retractable and swinging blade having its rear end supported on the chain; and operating means to impart said movements to the blade.

'7. In a switch of the character described, a retractable and swinging blade; sprockets and a chain carrying the blade; and means to impart movements to the blade.

TOMLINSON F. JOHNSON. 

